Filter cartridges of this kind are used for filtering air flows and gas flows, including in vehicle air conditioning systems. German utility model patent 43 23 522 deals with a filter cartridge in which an accordion-folded filter element is retained in a frame made of U-shaped strips. The production of such a filter cartridge, particularly of the frame, entails a relatively substantial outlay, since expensive tools are needed for the purpose. It is economically worthwhile to produce the tools only if rather large series are to be fabricated.